Protective gear for a limb

ABSTRACT

A protective body guard ( 10 ) providing a full range of motion that closely tracks the biomechanical movement of a joint. The device provides protection against sharp objects, impact and limb movement into positions that may cause injury. The device ( 10 ) comprises successive segments ( 12, 14, 16, 18, 20, 22 ) made of a hard, impact-resistant, light material and arranged in overlapping fashion and interconnected by means of a single pivot pin ( 28 ) or flexible strap in an arcuate slot ( 30 ) at each side of the segments. Cushioning pads ( 24, 26 ), detachably fixed to the segments ( 12, 22 ), provide protection from contact with the interior of the segments.

FIELD OF THE INVENTION

This invention relates to protective body gear. In particular thisinvention relates to articulated body gear for protecting joints againstinjury from sharp objects.

BACKGROUND OF THE INVENTION

Many types of activities require the use of protective covering to guarda user's body against the impact of potentially damaging objects.Generally speaking, the covering material for the protective gear shouldbe hard or resilient to withstand impact and sharp objects, the gearshould be shaped to correspond to the shape of the body parts to beprotected, and the gear should be articulated for unrestricted movementof the limbs.

Sports-oriented protective body guards are well known. U.S. Pat. No.5,794,261 to Hefling discloses protective gear for contact sports, whichcomprises a plurality of interlocking segments. Each segment comprisesan upper part and a lower part. Adjacent segments are made to overlapsuch that the upper part of one segment overlays the lower part of theadjacent segment. Adjacent segments are interconnected by means of holesin their lateral posterior portions. The holes are aligned when theadjacent segments are overlapped and a pivot pin extends through theholes on both overlapping segments. This allows adjacent segments topivot in relation to one another and to allow the upper part of onesegment to slide over the lower part of the adjacent segment. Heflingalso discusses the provision of elongated slots in the lateral posteriorportion of the segments and stop pins extending through the slots andinto holes in the adjacent segment.

The Hefling design enables flexing and extension of the joint. However,most joints have a more complex mode of articulation than simply flexingand extension. For example, many members may also rotate about theirjoint, which the Hefling design does not accommodate despite Hefling'sstated object of achieving a full range of motion. In some cases, a fullrange of unrestricted joint motion over its several types of movement isextremely important. This is the case for example for tree fellers whoneed unrestricted joint movement while climbing and felling trees usingheavy chain saws, for various sports, and for other activities.

There is therefore still a need for a protective body guard whichprovides a full range of motion that tracks more closely thebio-mechanical movement of a joint, while still ensuring continualcoverage of the body parts and protection against such sharp objects asthe blades of chain saws and other power tools, and protection againstfalls onto sharp objects and abrasive surfaces.

SUMMARY OF THE INVENTION

The present invention consists of protective gear for a leg or an elbowthat closely emulates the various movements of the joint. This ensuresthat the user is able to move the limbs in a relatively unrestrictedmanner, while still being protected from blows.

According to the invention, successive segments are arranged inoverlapping fashion and are interconnected by means of a single pivotelement in an arcuate slot at each side of the segments. The slot isangled in relation to the longitudinal axis of the extended limb. Thisallows the successive segments to not only flex and extend, but also torotate along with the limb and joint the gear protects. The protectivegear according to the invention also accommodates sliding, for examplewhen the femur sliding forward and backward on the tibia.

In one of its aspects, the invention comprises protective gear for ajointed limb comprising a plurality of partially overlapping,substantially rigid, segments. Each segment is adapted to articulate inrelation to the next adjacent segment to selectively flex and extendsubstantially along a longitudinal axis and to undergo limited rotationabout the longitudinal axis in relation to the other segments.Articulation between adjacent segments is accomplished by way of asingle pivot element on opposite sides of each segment, which extendsthrough an arcuate slot located in the adjacent segment.

In another aspect of the invention, the tangent to the center point ofthe arcuate slot defines an angle of between 10 and 65 degrees, andpreferably between 40 and 50 degrees, in relation to the longitudinalaxis of the extended gear.

In other aspects of the invention, the arc length of the slot is between15 mm and 25 mm and the slot has a radius of curvature of between 20 and55 mm.

In yet another aspect of the invention, the arcuate slot is located inthe superior posterior portion of the segment and the pivot element islocated in apertures in the inferior posterior portions of the segments.

In yet a further aspect of the invention, the arcuate slot is spacedbetween one half inch and one and a half inches from the lateral edge ofthe segment.

Other aspects of the invention will be appreciated by reference to thedetailed description of the preferred embodiment and to the claims thatfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment will be described by reference to the drawingsthereof in which:

FIG. 1 is a perspective view of the assembled leg and knee guardaccording to the preferred embodiment of the invention;

FIG. 2 is an exploded perspective view of the components of the leg andknee guard;

FIG. 3 is a perspective view of a thigh segment; and,

FIG. 4 is a perspective view of one of the intermediate segments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

Referring to FIG. 1, there is shown a leg and knee guard 10 according tothe invention. Guard 10 comprises generally a shaped thigh segment 12,smaller intermediate segments 14, 16, 18, 20 and a shaped shin segment22. The segments 12-22 are interconnected as described below.

Referring to FIG. 2, two cushioning pads 24, 26 are attached to theinside of segments 12 and 22 respectively, but pad 26 extends tounderlay segments 14, 16, 18 and 20 as well.

Successive segments 12 to 22 are interconnected by combination pins 28that extend through holes 36 at the inferior posterior portions of eachsegment and slightly arcuate slots 30 located at the superior posteriorportions of the next adjacent segment. Dacron straps 32 and strings 34are also provided as discussed below.

Segments 12-22 are made of a hard, impact-resistant but light material.The design of the pivot/slot arrangement (defined by pins 28, holes 36and slots 30) enables the segments and the overall body guard to closelyfollow and emulate the biomechanical behaviour of the leg and knee. Theoverall arrangement of the invention provides six degrees of freedom andallows rotation of the segments about each of the three main axes.

FIG. 3 illustrates a thigh segment 12 while FIG. 4 illustratesintermediate segment 14. The interconnection of successive segments willbe described by reference to the interconnection of segments 12 and 14,it being understood that successive segments are interconnected insubstantially the same way, save for possible variations to accommodateparticular joint or member articulation characteristics or shapes.

Circular holes 36 are provided in the inferior posterior portions ofeach segment. Holes 36 receive combination pivot pins 28 that alsoextend through arcuate slots 30 that are provided in the superiorposterior portions of the next adjacent segment. Thus a pin 28 extendsthrough hole 36 of segment 12 and through slot 30 of segment 14.

Two holes 36 of each segment are located across from each other at thelower left-hand corner and lower right-hand corners of the segment. Thiscreates an axis of movement between them.

The width of slots 30 is slightly larger than the width of thecombination pivot pins 28 to allow the pins 28 to slide smoothly alongthe slots. The arc length of the slot in the preferred embodiment isabout 20 mm and the radius of curvature is about 30 mm. It iscontemplated that arc lengths of between 15 mm and 25 mm and radii ofcurvature between 20 mm and 55 mm will be functional and within thescope of the invention.

The center tangent to each slot defines an angle to the longitudinalaxis of the leg (i.e. at an angle to the longitudinal axis of theextended guard). While a variety of angles between 10 and 65 degreeswill substantially accomplish the objective of allowing freedom ofmovement in several dimensions, the preferred angle is about 45 degrees.This arrangement allows movement of adjoining segments 12, 14, 16, 18,20 22 to accommodate a full range of motion of a human leg and knee,i.e., bending, flexing and extension, and rotation. Flexure andextension is provided by rotation of pin 28 in the slot (withoutnecessarily involving any sliding along the slot). Some rotation betweensuccessive segments is also provided by the sliding of the pins 28 alongthe slots 30, provided the slots are angled to the vertical/longitudinalto allow some lateral travel of the pin 28 in relation to thelongitudinal axis of the elongated body guard. As most rotation of a legor arm about a joint is done while also flexing or extending, the angledslot is well adapted to accommodate both types of movementsimultaneously and efficiently. This same angle of the slot to thevertical/longitudinal also allows a degree of sliding of the member onthe joint in the posterior-anterior direction.

The specific position of the apertures 36 and slots 30 in relation tothe segments on which they are provided also plays a role in allowingfreedom of movement between the segments. When successive segments aresubstantially identical in size and shape, placing the apertures andslots too far laterally on the segments may result in close contactbetween interconnected segments along the whole portion of theirsurfaces that are overlapping. The resulting friction would restrictrelative flexing movement between them. Ideally when the guard is fullyextended (unflexed), an overlap spacing is provided between the centerportions of adjacent segments to allow unrestricted flexing. Accordinglythe apertures and slots are provided at a somewhat recessed location inrelation to the lateral sides of the segments. The degree of recess willdepend principally on the degree of curvature of the segment and thedegree of anticipated flexing. However in the preferred embodimentscontemplated for leg and knee guards and arm and elbow guards, theapertures and slots are preferably recessed between about one half of aninch and one and a half inches from the lateral side edge of thesegments.

Four pins 38 are also provided in the middle portions of segments 12 and22 to secure Dacron straps 32 that extend to loosely interconnectsuccessive segments when the guard is not flexed. The Dacron straps 32are connected to the successive segments by way of rivets placed in themiddle holes 44 of said successive segments. The length and looseness ofthe straps 32 is selected to limit the maximum flexure of the guard. Theflexing of the guard results in a tightening of the straps 32 to limitfurther flexing. This provides support for the joint and also preventsthe introduction of a gap between segments from over-flexing.

Additional apertures 40 are provided on selected segments (in this caseon the thigh segment 12 and the shin segment 22) to receive strings 34that are used to tie the protective gear to the user's thigh and shin.Cushioning pads 24 and 26 are secured to the inside surface of selectedsegments by means of hook and loop type fasteners 58.

In one embodiment of the invention, thigh segment 12 further includes anelongated slot near the uppermost edge thereof. The elongated slot isused to receive a belt, strap or buckle used for securing the top of theprotective gear to clothing worn by the user. The elongated slot allowslateral movement of the thigh segment 12 in relation to the clothing.This serves to accommodate the relative twisting between the protectivegear (in particular the thigh segment 12) and the thigh of the userduring twisting of the leg.

Intermediate segments 16, 18 and 20 are identical to the segment 14 insize and shape as well as in the locations and sizes of apertures andslots except they also include a pair of brake slats 46. Brake slats 46serve to restrict over-extension of the adjacent segments.

The apertures 36 and the slots 30 are located such that when pins 28extend through them, the adjacent segments partially overlap one toensure continuous coverage of the joint or member over which thesegments lie.

In the preferred embodiment, each combination pivot pin 28 consists of apair of opposed mating pins 54 and Teflon washers 56. Combination pivotpins 28 can be easily removed to replace segments as required.Alternatively the pins 28 can be formed integrally with the segments. Acap, lock nut or other equivalent element can be secured to the tip ofthe pin after assembly of adjacent segments.

In an alternative embodiment, combination pins 28 may be replaced byflexible straps. In one version of the strap embodiment, eachcombination pin 28 is replaced by a flexible strap. The straps may besecured to a segment by threading it through a pair of closely parallelapertures or slots on the segment, such parallel anchoring apertures orslots corresponding to holes 36 of the preferred embodiment. The strapmay have a flat lateral extent that is able to extend along a portion ofthe slot 30 and to slide laterally along the slot. In another version ofthe strap embodiment, the plurality of combination pins 28 on one sideof the protective gear are all replaced by a single flexible strap thatis threaded through the anchoring apertures or slots and arcuate slots30 of successive segments.

The inventor has found that the use of straps has the advantage ofreduced noise during movement and flexure of the protective gear.Provided the strap is narrower than the length of the arcuate slot 30and can travel along the slot, the strap effectively provides at leastthe same freedom of movement as the combination pins of the preferredembodiment. The strap embodiment also obviates the need for Dacronstraps 32.

It will be appreciated that while the invention has been described byreference to the presently contemplated preferred and alternativeembodiments thereof, certain modifications and variations thereto may bepractised without departing from the spirit and scope of the invention.

What is claimed is:
 1. Protective gear for a jointed limb comprising aplurality of partially overlapping, substantially rigid, segments, eachof said segments being adapted to articulate in relation to the nextadjacent segment to selectively flex and extend substantially along alongitudinal axis and to undergo limited rotation about saidlongitudinal axis in relation to others of said segments, saidarticulation between a given segment and the next adjacent segment beingaccomplished by means at opposed sides of each of said segments, each ofsaid means comprising an arcuate slot in said given segment and a singlepivot element associated with said next adjacent segment, said pivotelement extending through said arcuate slot.
 2. Protective gear as inclaim 1 wherein said pivot element is a pivot pin.
 3. Protective gear asin claim 1 or 2 wherein said pivot element is integrally formed withsaid next adjacent segment.
 4. Protective gear as in claim 1 whereinsaid arcuate slot has a center point the tangent to which defines anangle of between 10 and 65 degrees in relation to said longitudinalaxis.
 5. Protective gear as in claim 4 wherein said angle is between 40and 50 degrees.
 6. Protective gear as in claim 1 wherein the arc lengthof the arcuate slot is between 15 mm and 25 mm.
 7. Protective gear as inclaim 6 wherein said arc length is about 20 mm.
 8. Protective gear as inclaim 1 wherein said arcuate slot has a radius of curvature of between20 and 55 mm.
 9. Protective gear as in claim 8 wherein said radius isabout 30 mm.
 10. Protective gear as in claim 4 or 5 wherein said pivotelement is a pivot pin.
 11. Protective gear as in claim 1 wherein saidprotective gear is a leg and knee guard, said protective gear furtherincluding a shaped thigh segment and a shaped shin segment. 12.Protective gear as in claim 7 further comprising at least one cushioningpad extending under at least two of said segments.
 13. Protective gearas in claim 7 wherein said pivot elements are pivot pins extendingthrough apertures in the inferior posterior portions of said segmentsand said arcuate slots are formed in the superior posterior portions ofsaid segments.
 14. Protective gear as in claim 9 wherein said aperturesand said arcuate slots are spaced in relation to the lateral edges ofsaid segments.
 15. Protective gear as in claim 10 wherein said spacingis between one half inch and one and a half inches.
 16. Protective gearas in claim 11 further comprising at least two straps each of saidstraps being secured to at least two of said segments.
 17. Protectivegear as in claim 1, 4,
 5. 6 or 7 wherein said pivot element is a strapof flexible material.
 18. Protective gear as in claim 7 wherein saidpivot elements are flexible straps extending through apertures in theinferior posterior portions of said segments and said arcuate slots areformed in the superior posterior portions of said segments. 19.Protective gear as in claim 18 wherein a single flexible strap isthreaded through the apertures and arcuate slots of successive segmentson each side of said gear.